abjs.module in A/B Test JS 8

Write test JavaScript.

File

abjs.module

<?php

/**
 * @file
 * Write test JavaScript.
 */
use Drupal\Core\Database\Database;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Render\Markup;

/**
 * Implements hook_help().
 */
function abjs_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {

    // Main module help for the block module.
    case 'help.page.abjs':
      return '<h3>' . t('See the <a href="@documentation">Module Documentation</a> for a detailed description of the module and instructions.', [
        '@documentation' => 'https://www.drupal.org/node/2716391',
      ]) . '</h3>';
  }
}

/**
 * Implements hook_page_attachments().
 */
function abjs_page_attachments(array &$page) {
  if (\Drupal::service('router.admin_context')
    ->isAdminRoute()) {
    return;
  }

  // Get all active tests that have at least one experience.
  $tests = Database::getConnection()
    ->query("SELECT DISTINCT t.tid FROM {abjs_test} AS t LEFT JOIN {abjs_test_condition} AS tc ON t.tid = tc.tid INNER JOIN {abjs_test_experience} AS te ON t.tid = te.tid WHERE t.active=1")
    ->fetchAll();

  // At least one test with at least one condition and at least one experience.
  // must be active for any script to be added to the page. Because of this,
  // we don't need a similar check later for conditions and experiences
  // individually.
  if (empty($tests)) {
    return;
  }

  // The following section prints out javascript objects for the active tests,
  // conditions, and experiences.
  $abjs_script = abjs_generate_js($tests);
  $page['#attached']['html_head'][] = [
    [
      '#tag' => 'script',
      '#value' => Markup::create($abjs_script),
      '#weight' => -100,
    ],
    'abjs_script',
  ];
}

/**
 * Builds the javascript for all active and valid A/B tests.
 *
 * @param array $tests
 *   An array of database result objects from a query on abjs_test to get all
 *   active and valid tests.
 *
 * @return string
 *   A string of javascript for running all tests.
 *
 *   - abTests will be an array of test objects. Each abTest object has these
 *     properties:
 *   -- name: The name of the test, equal to the test id. This will be used as
 *      the name of the cookie that gets assigned this test, prefixed by
 *      abjs_cookie_prefix from the variables table.
 *   -- conditions: An array of condition strings with the names of the
 *      condition functions to run. The condition strings are prefixed by con_,
 *      followed by the primary id from the test table and primary id from the
 *      condition table, which is used instead of the condition table so that we
 *      don't get duplicate function definitions with the same name.
 *   -- experiences: An array of experience objects. Each experience object has
 *      these properties:
 *   --- name: The name of the experience, equal to the experience id. This will
 *       be used as the value of the cookie that gets assigned for this test.
 *   --- fraction: The probability of this experience getting chosen. If all
 *       experience probabilities for a single test add to less than 1, the
 *       remainder is the probability that a user will not be in the test on
 *       each page hit. If probabilities add to greater than 1, experiences may
 *       have less than their stated probability of occurring.
 *   --- script: The name of the function for this experience. The name is
 *       prefixed by exp_, followed by the primary id from the test table and
 *       primary id from the experience table, which is used instead of the
 *       experience table so that we don't get duplicate function definitions
 *       with the same name.
 *   - abConditions will be an array of condition functions that apply to the
 *     active tests, named the same as abTest.conditions above, and using the
 *     condition script from the condition table.
 *   - abExperiences will be an array of experience functions that apply to the
 *     active tests, named the same as abTest.experiences above, and using the
 *     experience script from the experience table.
 */
function abjs_generate_js(array $tests) {
  if (empty($tests)) {
    return '';
  }
  $tests_js = [];
  for ($i = 0; $i < count($tests); $i++) {

    // Set name of this test to the tid.
    $tests_js[$i] = [
      'name' => "t_{$tests[$i]->tid}",
      'conditions' => [],
      'experiences' => [],
    ];

    // Get all conditions associated with this test,and make functions for the
    // scripts.
    $conditions = Database::getConnection()
      ->query("SELECT tc.tid, tc.cid, c.script FROM {abjs_condition} AS c INNER JOIN {abjs_test_condition} AS tc ON c.cid = tc.cid WHERE tc.tid = :tid", [
      ':tid' => $tests[$i]->tid,
    ])
      ->fetchAll();
    for ($j = 0; $j < count($conditions); $j++) {
      $tests_js[$i]['conditions'][$j] = $conditions[$j]->script;
    }

    // Get all experiences associated with this test and their fractions, make
    // a name for the value of the test cookie, and make functions for the
    // scripts.
    $experiences = Database::getConnection()
      ->query("SELECT te.tid, te.eid, e.script, te.fraction FROM {abjs_experience} AS e INNER JOIN {abjs_test_experience} AS te ON e.eid = te.eid WHERE te.tid = :tid", [
      ':tid' => $tests[$i]->tid,
    ])
      ->fetchAll();
    for ($j = 0; $j < count($experiences); $j++) {
      $tests_js[$i]['experiences'][$j] = [
        'name' => "e_{$experiences[$j]->eid}",
        'fraction' => $experiences[$j]->fraction,
        'script' => $experiences[$j]->script,
      ];
    }
  }

  // These are the only php variables referenced in the script below.
  $cookie_prefix_var = \Drupal::config('abjs.settings')
    ->get('cookie.prefix');
  $cookie_lifetime_var = \Drupal::config('abjs.settings')
    ->get('cookie.lifetime');
  $cookie_domain_var = \Drupal::config('abjs.settings')
    ->get('cookie.domain');
  $cookie_secure_var = \Drupal::config('abjs.settings')
    ->get('cookie.secure');
  $cookie_prefix = !empty($cookie_prefix_var) ? $cookie_prefix_var : 'abjs_';
  $cookie_lifetime = !empty($cookie_lifetime_var) ? $cookie_lifetime_var : '30';
  $cookie_lifetime = floatval($cookie_lifetime);
  $cookie_domain = !empty($cookie_domain_var) ? '; domain=' . $cookie_domain_var : '';
  $cookie_secure = !empty($cookie_secure_var) ? '; secure' : '';
  $js_vars = [
    'tests' => $tests_js,
    'cookiePrefix' => $cookie_prefix,
    'cookieDomain' => $cookie_domain,
    'cookieLifetime' => $cookie_lifetime,
    'cookieSecure' => $cookie_secure,
  ];
  $json = json_encode($js_vars);

  // abjs-common.js is the core functionality of the A/B testing javascript
  // framework. Visitors that pass the assigned condition scripts for each test
  // will be randomly placed and cookied into an experience for that test,
  // based on assigned probabilities for each experience. Each experience has
  // an associated script that is run for that experience, and all applicable
  // experience scripts are executed for each visitor on every page load, in
  // the order in which the tests are defined. The user will have one cookie
  // for each active test.
  $common_js = file_get_contents(drupal_get_path('module', 'abjs') . '/js/abjs-common.js');
  $abjs_script = "'use strict'; (function() {var abjs = {$json};\n{$common_js}})();";
  return $abjs_script;
}

Functions

Name	Description
abjs_generate_js	Builds the javascript for all active and valid A/B tests.
abjs_help	Implements hook_help().
abjs_page_attachments	Implements hook_page_attachments().